Smart Dust Unique Low Power Flexible Sensor Networks

Smart Dust: Unique Low Power Flexible Sensor Networks Maryland Sensor Network Group Neil Goldsman, Martin Peckerar, Quirino Balzano, Shuvra Bhattacharyya, Reza Ghodssi, Gilmer Blankenship Dept. of Electrical and Computer Engineering University of Maryland College Park

Outline: Focus on Hardware for Achieving Smart Dust Motes and Working Network 1. 2. 3. 4. 5. 6. Overview Power Efficient Micro RF Circuits Digital Low Power Circuits and Networking Ultra Small Antennas Energy: Micro Super Capacitor-Battery Energy Harvesting: RF & RF

Overview: Smart Dust Hardware Smart Dust Node • Analog Transceiver • Microprocessor ~1 mm – Communication and Sensor Control – Decision making • Micro-Battery • Energy Harvesting • Micro-Antenna /power Smart Dust Particle

Low Power Transceiver Design Thomas Salter, Bo Yang, Bo Li, Yiming Zhai and Neil Goldsman

Work Summary • Last January 2008 Review: – Tested 2. 2 GHz OOK receiver. • Successfully demodulated digital signal • Still required DC bias, integration with transmitter, integration with digital control, and integration with antenna. – Tested 2. 2 GHz OOK Transmitter: • Operated but frequency lower than expected. • Individual die components operated in accordance with design – Initial studies for benefits of FSK Transceiver began • Current February 2009 Review: – 2. 2 GHz OOK Receiver and Transmitter fabricated and operating as designed, communicating proved in test. – Integrated Transmitter and Receiver onto one chip, PCB test hardware developed – Improved isolation of transmitter and receiver – Designed bias circuits, under fabrication for 2. 2 GHz OOK receiver – Designed and fabricated and Tested: 2. 2 GHz FSK. – Designed and fabricated 10 GHz LNA – Designed 20 GHz FSK, under fabrication. – Designed 20 GHz ASK, under fabrication. – Fabricated part COTS part custom Transceiver with 2 cm footprint – Initial studies for UWB transceiver began.

Communication between 2. 2 GHz TX-RX TX Layout Simplified Schematic Drawing RX Measured results Data rate: 20. 16 k. Hz (up to 300 k. Hz) Yellow: RX output, -0. 6 ~0. 6 V, AC coupling (x 5 cable) Blue: TX fed-in data: 0~0. 9 V generated by function generator

2. 2 GHz Transceiver with on chip Power Control switch TX Power rail Control Switch RF Switch RX

2. 2 GHz FSK Receiver using Ultra Low Power Mixer Receiver Test Results: • • • Signal at buffered osc • BFSK Input: 2. 2 GHz+8 MHz freq modulation • 8 MHz lock-in frequency (limited by signal generator) Output of FM receiver. FM Input: 2. 2 GHz FM+1 MHz modulation

20 GHz Receivers 20 GHz ASK Receiver, under fabrication 20 GHz FM Receiver, under fabrication Can detect a 2 MHz freq difference in 35 MHz (20. 719~20. 754 GHz) lock-in range Ultra Low Power mixer and amplifier

OOK Receiver: Fabrication and Results • fabricated utilizing 130 nm IBM process

Improvement Over the Past Year Prior Generation Measurements Receiver Performance Sensitivity (BER=10 -3) Power Consumption Energy per Bit Data Rate New Generation Measurements -50 d. Bm 2. 77 m. W 2. 77 n. J/bit 1 Mbps Single-Stage LNA Performance Gain 13 d. B Power Consumption 2. 7 m. W Noise Figure 3. 4 d. B RF Scavenging Demodulator Gain vs Voltage Rectifier 10. 6 d. B Power Consumption 0 m. W Baseband Voltage Gain Filter Bandwidth (3 d. B) Power Consumption 30 d. B 1 MHz. 07 m. W Receiver Performance Sensitivity (BER=10 -3) Power Consumption Energy per Bit Data Rate -90 d. Bm 1. 55 m. W 1. 5 n. J/bit 1 Mbps Multi-Stage LNA Performance Gain 45 d. B Power Consumption 1. 5 m. W Noise Figure 3. 6 d. B RF Scavenging Demodulator Gain vs Voltage Rectifier 17. 6 d. B Power Consumption 0 m. W Baseband Voltage Gain Filter Bandwidth (3 d. B) Power Consumption 30 d. B 1 MHz. 05 m. W 40 d. B more sensitive while consuming almost 50% less power!

Comparison to Other Receiver Designs Presented in the Literature More sensitive Less power Better Prior work by other in the field achieves excellent sensitivity OR very low power consumption. This work is unique in that it achieves BOTH.

Digital/Low Power Design and Optimization for the Maryland Smart Dust Project Chung-Ching Shen, Roni Kupershtok, Shuvra Bhattacharyya and Neil Goldsman, with contributions from William Plishker February, 2009

Design Flows for the Smart Dust Digital System Application development software Implementation using C Implementation using Verilog Download hex file to hardware prototypes Design tool Synopsys Synthesis Design tool FPGA Synthesis (Xilinx ISE) Download binary file to Xilinx FPGA ASIC Compile source code to generate hex format output file hardware Design tool Verilog Simulator (Model. Sim) FPGA platform MCU platform Design tool IAR Embedded Workbench Floorplanning Placement Routing Fabrication

Design Summary for the Smart Dust Digital ASIC Application – Distributed Line-crossing Recognition (DLCR) Design summary – 8 major modules and 12 sub modules for implementing DLCR algorithm and TDMA protocols – All the modules have been implemented with Verilog. HDL. – All the modules have been tested and verified with a FPGA developing platform. – I/O interfaces are designed for interacting with analog transceiver modules Receive. Packet. Filter Clock. Counter Control Pre. Sync Unit Control S e n s Core e Transmit. Packet 15

Mixed-signal Integration for the Smart Dust Digital/Analog ASICs Analog transceiver modules Smart dust digital ASIC RX data RX control TX data Digital ASIC

Fabricated Chip for the Smart Dust Digital ASIC Process: MOSIS AMI 0. 5 µm Voltage: 5 V Target Freq: 20 KHz Power : 1. 2 m. W Chip Size: 2. 4 mm 2 Pads: 40 (including test pins) Process: IBM 0. 13 µm Voltage: 1. 2 V Target Freq: 20 KHz Power : 0. 014 m. W Chip Size: 1. 0 mm 2 Pads: 20 (including test pins) Process: MOSIS AMI 0. 5 µm Chip Size: 2. 4 mm 2 # of Transistors: ~ 30, 000 17

Testing Results for the Smart Dust Digital ASIC 0 transmits data to ASIC 1 via wired connection ASIC 1 ASIC 0: Transmitted data ASIC 1: Have received data and validated it ASIC 0 Data validation: ID must be matched as well as parallel bit check 18

Generations for the Smart Dust Fabrication Chip design Mote Packaging 0. 24 cm Smart dust digital ASIC (microprocessor) TX 0. 2 cm Smart dust transceiver ASICs RX 0. 2 cm FPGA-MCU PCB design 3 cm 1. 4 cm MCU 1. 2 cm 4 cm MCU 19 2 cm

Power and Size Comparison for Sensor Network Hardware Systems Size Tmote Sky [2] *Power: 58. 5 m. W Size: 32 X 80 mm SHIMMER [1] *Power: 54 m. W Size: 50 X 25 X 12. 5 mm SNo. W 5 [3] *Power: 73. 1 m. W Size: 50 X 85 mm Btnode [5] *Power: 105 m. W Size: 58 X 33 mm. Mica 2 [6] Mica. Z [4] *Power: 117 m. W *Power: 88. 2 m. W Size: 58 X 32 X 7 mm Mica 2 Dot [7] *Power: 117 m. W Size: 25 X 6 mm Smart Dust *Power: 4. 8 m. W Size: 20 X 14 X 12 mm *CPU on, Radio RX/TX on Power

References [1] B. Kuris and T. Dishongh. SHIMMER Hardware Guide Rev 10, October 2006. (http: //www. eecs. harvard. edu/~konrad/projects/shimmer/) [2] Moteiv Tmote Sky Datasheet, November 2006. (http: //www. moteiv. com/) [3] M. Baunach, R. Kolla, and C. Muhlberger. Snow 5: a modular platform for sophisticated real-time wireless sensor networking, Institut fur Informatik, University of Wuerzburg, Technical Report 399, January 2007. [4] MICAz Datasheet Rev A. Crossbow. (http: //www. xbow. com/) [5] BTnode rev 3 Hardware Reference. ETH Zurich. (http: //www. btnode. ethz. ch/) [6] MICA 2 Datasheet Rev A. Crossbow. (http: //www. xbow. com/) [7] MICA 2 Dot Datasheet Rev A. Crossbow. (http: //www. xbow. com/) 21

• Journal – – • Publications C. Shen, R. Kupershtok, S. Adl, S. S. Bhattacharyya, N. Goldsman, and M. Peckerar. Sensor support systems for asymmetric threat countermeasures. IEEE Sensors Journal, 8(6): 682 -692, June 2008. C. Shen, W. Plishker, D. Ko, S. S. Bhattacharyya, and N. Goldsman. Energy-driven distribution of signal processing applications across wireless sensor networks. Submitted to ACM Transactions on Sensor Networks. Conference – – – C. Shen, W. Plishker, and S. S. Bhattacharyya. Design and optimization of a distributed, embedded speech recognition system. Proceedings of the International Workshop on Parallel and Distributed Real-Time Systems, Miami, Florida, April 2008. M. Peckerar, C. Shen, S. S. Bhattacharyya, and N. Goldsman. Integrated Multi-layer Design of Ad -Hoc Smart Small Sensor Networks. Proceedings of the Government Microcircuit Applications and Critical Technology Conference, Las Vegas, Nevada, March 2008. C. Shen, W. Plishker, S. S. Bhattacharyya, and N. Goldsman. An energy-driven design methodology for distributing DSP applications across wireless sensor networks. Proceedings of the IEEE Real-Time Systems Symposium, Tucson, Arizona, December 2007. C. Shen, R. Kupershtok, S. S. Bhattacharyya, and N. Goldsman. Design and implementation of a device network application for distributed line-crossing recognition. Proceedings of the International Semiconductor Device Research Symposium, College Park, Maryland, December 2007. C. Shen, R. Kupershtok, S. S. Bhattacharyya, and N. Goldsman. Design techniques for streamlined integration and fault tolerance in a distributed sensor system for line-crossing recognition. Proceedings of the International Workshop on Distributed Sensor Systems, Honolulu, Hawaii, August 2007. C. Shen, R. Kupershtok, B. Yang, F. M. Vanin, X. Shao, D. Sheth, N. Goldsman, Q. Balzano, and S. S. Bhattacharyya. Compact, low power wireless sensor network system for line crossing recognition. Proceedings of the International Symposium on Circuits and Systems, New Orleans, 22 Louisiana, May 2007.

Efficient Antennas for Motes Dimensions << λ/4 BO YANG, XI SHAO, Q. BALZANO AND NEIL GOLDSMAN

Work summary • Last January 2008 Review: – Fabricated FICA for 2. 2 GHz /2. 4 GHz with 1. 1 mm x 1. 1 mm ground plane. – Tested 2. 2 GHz FICA outdoor. – Measured FICA performance with in-house designed On-Off Keying (OOK) receiver – Developed circuit model of FICA – Expected 3 D integration of transceiver, with lowest form factor in the world – Investigation of ground plane size effect under way • Current February 2009 Review: – Applied FICA circuit model into system design optimization. – Measured 916 MHz and 2. 2 GHz FICA radiation pattern in Anechoic Chamber – Implemented 3 D integrated transceiver, with world’s record low form factor. – Tested 20 mm x 15 mm radio (including FICA, radio, sensor, battery, etc. )

Short Review of ESAs • ESA is: – a radiating resonator – compact and efficient – minimum ohmic losses – short transmission line • To Radiate ESA: – Need large currents and large e-fields over the small volume (resonance) – Need impedance transformer to feed with 50 – Need low loss materials • ESA Plusses – Small volume – More room for electronics – Attractive product looks – High tech impression – Wide applicability – Low manufacturing cost • ESA Minuses – Adverse reactance ( l or 1/ c) – Low radiation resistance (m ) – Low effiency (ohmic losses) – Narrow band – Low gain – Difficult to match to 50

An Efficient ESA: FICA (F-Inverted Compact Antenna) • Transmision line propagation constant k=ω√LC • Helical transmission line (high L) • Strong coupling to ground (high C) • Short helix resonant size • Minimum number of turns • Embedded reactive impedance transformer • Strong electric dipole radiation current

2. 45 GHz FICA Integrated with a Mote Exposed part is the antenna 7 mm 12 mm 3. 5 mm 4 mm Full transceiver radio and battery is enclosed in the black box. 20 mm Microphone sensor • The wave length at 2. 45 GHz is 12. 24 cm. • The dimension of 2. 45 GHz FICA is shown in the photo.

FICA Radiation Pattern FICA tested in anechoic chamber, radiation pattern matches simulation.

FICA vs. COMPETION

FICA Equivalent Circuit for System Optimization

FICA Publications • Patent: – B. Yang, F. Vanin, X. Shao, Q. Balzano, N. Goldsman, G. Metze, Low Profile F-Inverted Compact Antenna (FICA), filed by University of Maryland, Jun. 2007, patent pending. • Journal: – B. Yang, X. Shao, Q. Balzano, N. Goldsman, G. Metze, “ 916 MHz F-Inverted Compact Antenna (FICA) for highly integrated transceivers, ” Antennas and Wireless Propagation Letters, to be published. • Conference: – B. Yang, X. Shao, Q. Balzano, N. Goldsman, “ Integration of small antennas for ultra small nodes in wireless sensor networks, ” in IEEE International Semiconductor Device Research Symposium Dig. (ISDRS), College Park, MD. USA. , Dec. 2007. – B. Yang, F. Vanin, C. Shen, X. Shao, Q. Balzano, N. Goldsman, C. Davis, “A low profile 916 MHz F-Inverted Compact Antenna (FICA) for wireless sensor networks, ” in IEEE Antenna and Propagation International. Symposium. Dig. , pp. 5419 -5422, Honolulu, HI. USA. , Jun. 9 -15, 2007. – C-C. Shen, R. Kupershtok, B. Yang, F. Vanin, X. Shao, D. Sheth, N. Goldsman, Q. Balzano, S. S. Bhattacharyya, “Compact, low power wireless sensor network system for line crossing recognition, ” in IEEE International Symposium on Circuits and Systems (ISCAS), pp. 2506 -2509, New Oreland, LA. USA. , May 27 -30, 2007.

CONCLUSION • • • Extremely small antenna High efficiency for size Bandwidth compatible with theoretical q Radiation: isotropic as possible Performance better than or comparable to larger commercial antennas

433 MHz Body Antenna Q. Balzano, Bo Yang, Xi Shao, Neil Goldsman Presented in Classified Review

Flexible Thin Film Battery/Supercapacitor Hybrid Power Sources Martin Peckerar, Yves Ngu, Zeynep Dilli, Mahsa Dornajafi, Kwangsik Choi, Myunghwan Park and Neil Goldsman Department of Electrical and Computer Engineering University of Maryland College Park, MD 20742

Project Goals • To achieve a mechanically flexible power source that can conform to a range of surface topologies (electronic packaging material, bridge abutments, supporting struts, etc. ) • To create a galvanic cell/supercapacitor hybrid capable of long term, low power level sourcing as well as power “burst mode” operation • To create a power supply that is more easily charged by RF (and mechanical energy scavenger) sources: e. g. , a cell that recharges at low (~1 V) voltage • To create an “environmentally safe” power source to eliminate the toxicity issues associated with lithium

Basic Cell Cross Section Single cell Double stacked cell The electrolyte is made of a solution of ethylene glycol, ammonium hydroxide, boric acid + nitric acid OR phosphorus acid

We Have Successfully Run Smart Motes with the Ru. Ox Batteries

We Have Demonstrated Low. Voltage RF charging

We Have Demonstrated “Burst. Mode” Operation

We Have Driven Flexible Electronics Platforms With the Ru. Ox Cells

Comparison of Thin Film Galvanic Cells

Conclusions • WE HAVE DEMONSTRATED: – A FLEXIBLE THIN-FILM POWER SOURCE WITH GREATER STORAGE CAPACITY THAN ANY OTHER APPEARING IN THE LITERATURE – WE HAVE OPERATED THE “SMART DUST” MOTE IN FULL T/R MODE FOR OVER 4. 5 MINUTES – THE CELL EXHIBITS INTERESTING “REGENERATION” BEHAVIOR – WE HAVE DEVELOPED A LOW VOLTAGE RECHARGING CELL – WE HAVE USE OUR CELL TO OPERATE FLEXIBLE ELECTRONICS

Future • Ultra Low Power Transceivers – Ultra Wide Band Radios – Broad Band Antennas – Dedicated Signal Processing & Digital Control • Batteries for Networks – Planar – Geometrically Configurable – Remote Chargeability